AE eaten we Ste Pu Rees i ge 5 
va ~ sf 
358. REPORT OF THE COMMISSIONER OF AGRICULTURE. 
ceived by them from Evanston, Il1., in August, 1881, and from Cob- ._ 
den in June, 1884, and again from Columbia, Mo., in June, 1887, _ 
They add that Gleosporium venetum, Sacc., a Huropean species found 
on Rubus, has spores of about the same size as their G. necator, but 
the former occurs on the leaves of the host, while the American fun- 
gus is found on the canes. 
We have no specimens for comparison, but the description given 
by M. Spegazzini of Gleosporiwm venetum, published in 1877,* ap- 
plies perfectly tothe American fungus described by Ellisand Ever- 
hart in everything excepting that it is said to occur on the leaves. 
In the description of G. necator reference is only made to its oc- 
currence on the canes; the fact of its being very common on the leaves 
was apparently unknown to the authors of the species. Recent ob- 
servations have led to the discovery that no part of the plant above 
ground is free from the attacks of the parasite. It is occasionally 
seen attacking the fruit, and the petioles and veins of the leaves are 
often greatly disfigured by it. 
(6) EXTERNAL CHARACTERS OF THE DISEASE (Fig. 1). 
That the disease is directly due to the action of the fungus, which is 
a true parasite, there can be no question. 
On the canes.—The fungus attacks both fruiting and non-fruit- 
ing canes orsuckers. On the latter it usually appears first hear the 
base, producing small purple spots that are variously scattered around 
the cane. The spots first formed rapidly increase in size, and asthe 
fungus develops the center of each becomes grayish-white in color. 
Surrounding each spot is a slightly-raised, dark purple border, sep- 
arating the healthy from the diseased tissues. The course of devel- 
opment is from the lower portion of the canesupwards, so that at any 
time during the growing season the tip of the cane shows ony the f 
minute purple spots or early manifestations of the disease, while to- . 
wards its base are found the older and larger spots. In anadvanced 
stage of the disease the spots coalesce or run together, and appear as 
irregular blotches, which are frequently an inch and a half long, 
and sometimes completely encircle the cane. The direct damage to 
the tissues rarely extends to the pith; the greatest injury is confined 
to the cambium layer, or the portion through which the sap is con- 
veyed in the process of growth. Thus, nearly the same effect is pro- 
duced on the cane by the action of the fungus as would result to a 
living tree if girdled by the knife or ax. The living tissues of the 
dark border, two to three millimeters in diameter, orbicular or elliptical; spores 
oblong-elliptical, 5-7u by 3u, oozing out in an amber-colored mass through a single 
opening in the center of each spot. Reported as being very injurious. G.venetum, 
Sacc., has spores of about the same size but is a folicolous species. The Illinois speci- 
mens were reported as Phyllosticta necator, but the fungus is evidently a Glao- 
sporium. : 
*G. Venetum Spez. Spots marginate, without definite shape, large or small, and 
elevated in the center, honey or ocher yellow, surrounded by a dark purple border. 
Acervuli minute, prominent, gregarious, or solitary, dark; condidia oblong-elliptical 
7-8 by 24; granulose or nucleated, hyaline. In languishing leaves of Rubus Cham- — 
ceneorus. Belluno and Coneg. liano, Italy. Saccardo, Sylioge Fungorum, Vol.—, 
. 706. 
: There appears to be no good reason why a new name should be given our Amer- 
ican form, The specific character of many of the imperfect fungi, of which this | 
is one, are too often based upon characters that rarely remained fixed, and it is 
useless to multiply names which only lead to confusion, Therefore, Spegazzini’s 
name Glocosporium venetum, being the earlier one published, is here adopted. 
